Error upgrade 1.6 to 1.8

[root123]

Fatal error: Call to undefined method MyBB::get_input() in install\upgrade.php on line 162
?
line 162: $mybb->input['action'] = $mybb->get_input('action');

[.m.]

ensure that you have uploaded all files of the new version - reupload all files if required.

[root123]

ensure that you have uploaded all files of the new version - reupload all files if required.

thx .. new error
Data Cache Building
MyBB SQL Error
MyBB has experienced an internal SQL error and cannot continue.
SQL Error:1054 - Unknown column 'deletedthreads' in 'field list'QueryELECT SUM(threads) AS numthreads, SUM(posts) AS numposts, SUM(unapprovedthreads) AS numunapprovedthreads, SUM(unapprovedposts) AS numunapprovedposts, SUM(deletedthreads) AS numdeletedthreads, SUM(deletedposts) AS numdeletedposts FROM mybb_forums

[.m.]

you have to run the upgrade script again by correctly selecting your earlier forum's MyBB version

[root123]

thx :* :* :* :* :*